OAKLAND — A firefighter and three recycling company employees were treated Monday morning after being exposed to what authorities believe was a toxic mix of a powerful pesticide and household products at a North Oakland house.

Battalion Fire Chief Darin White said although officials are not totally certain of the cause, they believe that a glass container of DDT broke while a homeowner was removing it from a garage. Some of the liquid apparently spilled onto wood that was inadvertently placed into a recycling bin with household products used for cleaning and laundry.

The incident began about 8 a.m. when a driver for California Waste Solutions was picking up recyclables in the 100 block of Stonewall Road off Claremont Avenue, near the Claremont Hotel and Spa.

The driver became concerned because his face had a burning sensation and drove to company’s yard in the 1800 block of 10th Street, and then went to a clinic for treatment. Two other recycling staffers who went to the Stonewall scene after the driver reported ill also became sick and went to the clinic, including one who was vomiting.

A firefighter who responded to the site also fell ill, with an itchy throat, cough and runny nose, and was taken to a hospital where he was treated and released, officials said. The employees were treated and released with first aid only and returned to work.

At the request of fire officials, the load brought to the recycling yard was taken to a secure area, where fire hazmat crews sorted through it to make sure there were no fumes. The recycling truck was decontaminated, according to Joel Corona, chief operations officer for the recycling company.

Corona cautioned customers that for their own safety as well as that of recycle employees and others, to be careful about what they put in bins. Chemicals, caustic substances and acids are prohibited from recycling bins.

Harry Harris is a Pulitzer Prize winning breaking news reporter for the Bay Area News Group. He began his Oakland Tribune career in September 1965 as a 17-year-old copyboy. He became a reporter in 1972 and is considered one of the best crime and breaking news reporters in the country. He has covered tens of thousands of murders and other crimes in the East Bay. He has also mentored dozens of young reporters, some of whom continue to work in journalism today.

Otto Warmbier was arrested in January 2016 at the end of a brief tourist visit to North Korea. He had been medically evacuated and was being treated at the University of Cincinnati Medical Center when he died at age 22.